Method of testing



Patented Oct. 13, 1931 UNITED STATES PATENT FF A Bonner n. 'BonnnY, or GLEN" amen, AND ILLiAM COLEMAN, OEKEARNY, new JERSEY, ASSIGNOR-S TO consortium-un air, INC; A coarona'rron or NEW Yonx concrete METHOD or 'rnsrme' 1 v No Drawing.

The present invention contemplates a novel method of determining the moisture content of concrete floors as a guide'in ascertaining the readinessof the floor. for the reception of an installation of linoleum. 1

It is a well known fact that linoleum or the like can not be successfully installed over a 'concrete fioor which contains more than a certain amount of free moisture. The. reason for this is that such moisture when present in excessive amounts forms an alkaline solution with certainyconstituents of the concrete and such solution acts to disintegrate the linoleum. Furthermore, because of'the fact that concrete is formulated inmany different ways and ispoured andallowedto set or harden under greatly'varying conditions, the period required for the moisture content to become reduced below the maximum safety point varies over wide limits. Accordingly, the elapsed period of time after the concrete has been poured is not a safe criterion of the dryness of the floor and it is therefore necessary to determine in each case whether the ceive the linoleum.

The conventional quantitative method heretofore used in determining the suitability of the floor, consisted in ascertaining the percentage of moisture in a sample taken therefrom by the loss in weight occasioned by heating. This method requires the facilities of a laboratory which is frequently unavailable and also the services of a trained analyst. In addition, a period of one to several days elapses between the time when the sample is taken and the receipt of report on the determination of the moisture content. Numerous simple qualitative methods have been proposed and, to some extent, used but none of these ofiers suflicient accuracy to be accepted as a reliable quantitative method.

It is the object of our invention to overcome all these disadvantages and to provide a quick, simple and reasonably accurate method of determining the readiness of a concrete floor for the reception of an installation of linoleum. More particularly, our

-tur.e rise willbe approximately 12 F. for

invention provides a method which is adapted to be carried out in situ and which Application filed January 21, 1930. Serial No. 422,483.

floor is in suitable condition to re- 1 may be completed within 15 to QOminutes. The method requiresneither the equipment of a laboratory nor the services of a trained analyst and may be readily and accurately performed by one unskilled in analytical methods. The above and other advantages will be readily apparent from the following description. 3 1

Our novel method is based upon the discovery that calciumcarbid'e or its equivalent when mixed in suitable form and amount with pulverized concrete, reacts exothermicallywith the free moisture therein, causing a rise in temperature which is directly proportional to the amount of moisture present. Briefly, themethod consists in sampling the concrete floor to be tested, pulverizing the sample, admixing in a suitable vessel a predetermined amount of the pulverized concrete with dry powdered calcium carbide, agitating the mix, ascertaining. the maximum rise in temperature and converting such temperature rise into terms of percent moisture. V

As a specific case, a sample is obtained from the concrete floor to be tested, by drill- ,ing. v This procedure accomplishes the pulverization of the sample simultaneously with its extraction from the floor. Twooubic centimeters (equivalent to approximately three grams by weightlofthe powdered con crete is then measured out by. means of a graduated cup and placed in a suitable vesselsuch as a test tube. An approxlmately equivalent amount,'that is, three (3) grams, of dry powdered l calcium carbide is placed in thevessel or test tube above the powdered concrete sample. The sample and calcium carbide are thenthoroughly agitated and as the calcium carbide reacts with the moisture ofthe concrete, heat is generated The maximum rise in temperature is noted by means off-a thermometer, preferably amaximum selfregistering thermometer. The extent 'of the temperature rise servesas a direct measure of the moisture content of the floor. W, hen carrying out the method with a sample of the size described above, the temperaeach percent ofmoisture present. By distallation of linoleum. 7 that our method is also "applicable in deterviding the maximum rise therefore by 12, the number of percent of moisture is readily determined and the suitability of the floor to receive an installation of linoleum may be ascertained.

F or convenience, the charge of dry powdered calcium carbide is preferably prepared prior to the test by Weighing out the desired amount and sealing the same in a glass tube, or the charge may be otherwise obtained in such form. This facilitates the test and avoids any diiiiculty which might be encountered in keeping the calcium carbide perfectly dry prior to its use.

Certain other substances, capable of reacting exothermic-ally with the free moisture in the concrete, may be used as equivalents for powdered calcium carbide in carrying out our method although because of its avail ability, cheapness and safety, calcium carbide is to be preferred. Among such other substances may be mentioned calcium phosphide, magnesium nitride, aluminum carb'ide and sodium peroxide.

it will be observedthat our invention fills a long felt need in providing a rapid and ample quantitative method of ascertaining in-situ the condition of concrete floors. By employing our method, one is able to deter mine promptly and without elaborate analytical equipment whether a floor is in suitable condition for the reception of an in- It will be apparent mining the moisture content of concrete or plaster walls to ascertain the COIldltlOIl of such surfaces for the reception-of'p'aint.

Claims: 7 1. A method of determining the suitability of concrete floors for the reception of an installation of linoleum which comprises the steps of sampling the concrete floor, tp'ulverizing the sample, admrxlng a'determmed amount of such sample Wlth an approximately equal amount of dry powdered "calcium carbide, agitating the constituents of the mix, and ascertaining the maximum *increase in temperature thereof.

2. Amethod of determining the suitability of concrete floors for the reception 'ofran installation of linoleum which comprises the steps of admixing a determined amountof a pulverized sample of the concrete floor with dry powdered calcium carbide, and ascertaining the maximum increase in temperature of the mix.

3. A method of determining the suitability of concrete floors for the reception of'an installation of linoleum which comprisesthe steps of admixing adeterminedamountof a pulverized sample of the concrete'floor with a substance capable of reaeting exothermicallywith the moisturein-said sample and ascertaining the maximum increase :in temperature ofthe'mix.

4. A method of determining the moisture content of concrete surfaces or the like which comprises the steps of sampling the surface, pulverizing the sample, admixing a determined amount of the pulverized sample With an approximately equal amount of dry powdered calcium carbide, agitating the constituents of the mix, ascertaining the maximum increase in temperature, and converting the temperature increase into terms of percent moisture.

5. A method of determining the moisture content of concrete surfaces or the like which comprises the steps of sampling the surface, pulverizing the sample, admixing a deter mined am'ount'of the pulverized sample with a substance capable of reacting exothermica lly with the moisture in said sample, agitating the constituents of the mix, ascertaining the maximum increase in temperature, "and converting said temperature increase into terms of percent moisture.

6. A method of determining the moisture content of concrete surfaces-or the like which comprisesithe steps :of admixing adetermine d amount of a pulverized sample of the concrete surface with dry powdered calcium carbide, and ascertaining the maximum increase in temperature of the mix.

In testimony whereof, Weafiix our signatu-res.

ROBERT D. BONNEY. WILLIAM B. COLEMAN. 

